Expose *ALLOW-OBSOLETE-SYNTAX*

Also: minor parser tweak for mailbox. We need to accept :dot-atom in
the display name portion, if obsolete syntax is enabled.

src/package.lisp

@@ -23,7 +23,7 @@
 
 (defpackage "DARTS.LIB.EMAIL-ADDRESS"
   (:use "COMMON-LISP")
-  (:export "*ALLOW-UNICODE*" "PARSE-RFC5322-ADDR-SPEC" 
+  (:export "*ALLOW-UNICODE*" "*ALLOW-OBSOLETE-SYNTAX*" "PARSE-RFC5322-ADDR-SPEC" 
            "PARSE-RFC5322-MAILBOX" "PARSE-RFC5322-MAILBOX-LIST"
            "ESCAPE-LOCAL-PART" "ESCAPE-DISPLAY-NAME" "ADDRESS" "ADDRESSP" 
            "ADDRESS-LOCAL-PART" "ADDRESS-DOMAIN" "ADDRESS-STRING" "ADDRESS-HASH" 

src/parser.lisp

@@ -397,6 +397,7 @@ an error, or when reaching the END index. The following error codes are defined:
          (parse-display-name (before after token value)
            (case token
              ((:atom :quoted-string :phrase) (push value phrase) (jump after #'parse-display-name))
+             ((:dot-atom) (if *allow-obsolete-syntax* (progn (push value phrase) (jump after #'parse-display-name)) (done :bad-display-name before)))
              ((:<) (setf display-name (finish-phrase)) (jump after #'parse-enclosed))
              ((nil) (done :missing-address before))
              (t (done :bad-display-name before)))))